GM3 (monosialodihexosylganglioside) is a type of
ganglioside
A ganglioside is a molecule composed of a glycosphingolipid (ceramide and oligosaccharide) with one or more sialic acids (e.g. N-acetylneuraminic acid, ''N''-acetylneuraminic acid, NANA) linked on the sugar chain. NeuNAc, an acetylated derivative ...
. The letter G refers to ganglioside, and M is for monosialic acid as it has only one
sialic acid
Sialic acids are a class of alpha-keto acid sugars with a nine-carbon backbone.
The term "sialic acid" () was first introduced by Swedish biochemist Gunnar Blix in 1952. The most common member of this group is ''N''-acetylneuraminic acid ...
group. The numbering is based on its relative mobility in electrophoresis among other monosialic gangliosides. Its structure can be condensed to
NANA
Nana, Na Na or NANA may refer to:
People
* Nana (given name), including a list of people and characters with the given name
* Nana (surname), including a list of people and characters with the surname
* Nana (chief) (died 1896), Mimbreño Ap ...
-
Gal-
Glc-
ceramide
Ceramides are a family of waxy lipid molecules. A ceramide is composed of sphingosine and a fatty acid joined by an amide bond. Ceramides are found in high concentrations within the cell membrane of Eukaryote, eukaryotic cells, since they are co ...
. GM3 is the most common membrane-bound
glycosphingolipid
Glycosphingolipids are a subtype of glycolipids containing the amino alcohol sphingosine. They may be considered as sphingolipids with an attached carbohydrate. Glycosphingolipids are a group of lipids (more specifically, sphingolipids) and are ...
in tissues, composed of three monosaccharide groups attached to a ceramide backbone.
GM3 serves as a precursor for other, more complex gangliosides. Like other gangliosides, GM3 is synthesized in the
Golgi apparatus
The Golgi apparatus (), also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic Cell (biology), cells. Part of the endomembrane system in the cytoplasm, it protein targeting, packages proteins ...
. It is then transported to the plasma membrane, where it functions in cellular signaling.
GM3 also functions as an inhibitor; it inhibits cell growth, the function of growth factor receptors, and generation of
cytokine
Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling.
Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...
s by
T cell
T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell ...
s.
Applications in cancer treatment
The immunologic function of GM3 in inhibiting proliferation has resulted in its usage in the study of cancer biology and cancer treatments. GM3 has been found to reduce the motility of ovarian cancer cells, colorectal cancer cells, and gastric cancer cells. High amounts of GM3 also displayed a high amount of
caveolin-1, a molecule which has been shown to inhibit ovarian cancer growth. In bladder cancer cells, GM3 show antiproliferative effects. Increased concentrations of GM3 in bladder cancer cells reduces the malignancy potential of those cells and induces apoptosis.
The addition of GM3 to bladder cancer cells also decreases their cell adhesion and inhibits tumor growth.
Due to its role in inhibiting cancer growth, GM3 is a target of cancer treatments. The chemotherapy drug
cisplatin
Cisplatin is a chemical compound with chemical formula, formula ''cis''-. It is a coordination complex of platinum that is used as a chemotherapy medication used to treat a number of cancers. These include testicular cancer, ovarian cancer, c ...
functions by inducing GM3-mediated
apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...
of cancer cells.
References
{{Sphingolipids
Glycolipids